Improvements in the outcome for women with breast cancer will require an emerging new breed of investigator, the translational researcher. Scientists with a strong foundation in basic molecular and cellular research who also have an understanding of the clinical disease will direct the most effective future of breast cancer research. Such investigators have been called "translational" because of their ability to translate basic findings into clinical strategies. This type of training requires both a well funded core of investigators performing basic laboratory research, and an excellent clinical training program. At Baylor College of Medicine, the Breast Center affords such a combination. This is a resubmission of competitive renewal of a Training Program begun 5 years ago which has supported 14 PhD or MD postdoctoral trainees. All trainees work on an aspect of breast cancer chosen from hormone action and therapeutic applications, growth factors, signal transduction, cell cycle control, normal.breast development, breast cancer prevention, breast cancer evolution, molecular genetics, or gene therapy. Formal didactic courses covering scientific writing and research grants, biostatistics, leadership skills, and problems in clinical translational breast cancer research are required. Progress and direction of the trainee's research project are closely monitored in weekly data reviews. Trainees also attend a weekly clinical breast cancer case conference in order to increase their understanding of clinical issues. Because of our integrative nature, and the balanced inclusion of MD and PhD mentors, the trainees have abundant opportunities to interact with their clinical counterparts for discussion of translational issues, and the majority of trainees have remained in academic research. Thus, by providing a program that involves laboratory training under the direction of well-established preceptors with a long-standing track record of breast cancer research, interaction with successful physician-scientists and exposure to clinical breast cancer issues, we have created a unique opportunity to train new translational researchers. This Program is highly relevant to the public health because there is a great need for more translational, multidisciplinary scientists to conquer the problem of breast cancer, since this disease accounts for the second most frequent cause of mortality in women in the United States.